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PISTON RING.

APPLICATION FILED 050.15. |919.

I 2 In wanton X N n". GLM/JJ/ @Hornets UNITED STATES PATENT OFFICE.

JOHN n. Nonwoon, or BALTIMORE, Manirnmn.

PISTON-RING.

Original No. 1,304,360, dated May 20, 1919, Serial No. 249,782, ledAugust 14, 1918. Application for reissuei led December 15, 1919. SerialNo. 345,132.

T 0 all whom 'it may concern.'

Be it known that I, J oHN E. Nonwoon, a citizen of the United States,residing at Baltimore, in the State of Maryland, have invented certainnew and useful Improvements in Piston-Rings, of which the following` isa speciiication.

This invention relates to improvements in piston rings and has for itsobject to provide a peripheral groove or annular recess in the ringarranged to receive the oil on the downstroke and distribute it evenlyand in a thin film over the surface of the cylinder during the upstroke,retaining sulficient of the oil in the groove between the surface of thering and the cylinder wall to act as an eifective seal, filling thecrevices and irregularities in the cylinder wall, preventing the escapeof gas by the piston, and preventing the entrance of oil into thecombustion space and the dilution of the lubricant by and with condensedfuel, and to provide a supplemental ring which coperates with the pistonring or rings to prevent the oil from working around and over the pistonrings to the firing chamber, and to preventA the gas in the firingchamber from passing around the piston ring, and also to provide meansto allow the oil that works under and back of the piston rings to dropback into the crank case.

The invention consists of the novel construction and arrangement of theparts and combination of parts hereinafter more fully set forth in thefollowing specification and pointed out in detail in the appendedclaims.

In the accompanying drawing,-

Figure 1 is a vertical section of a cylinder, the piston therein havingmy invention applied thereto.

Fig. 2 is an enlarged section of a portion of the cylinder and piston.

Fig. 3 is a modification showing the piston ring in two sections.4

Fig. 4 shows the .ring proper as used without the supplemental ring, theoil sealing groove being the important feature.

Referring to the accompanying drawings, forming part of thisspecification, and in which like reference numerals designate like partsthroughout the several views, 1 designates a cylinder and 2 the piston,the latter being operated in the i: linder through the medium of the rod3 eading to the crank-shaft (not shown) of the englne. The said pistonis provided with annular grooves 4 into which the piston rings 5 lit..Said rings 5 as shown each have overlapping ends 6, preferably cut toform a step Joint, the two ends presenting to eac-h other fiatcontacting surfaces 61 and annular recesses 7 ,between the bottom andtop face,

4more definitely the axial end surface 51, of

the ring and the contacting flat surfaces 61 of the joint. The shape andposition of the annular recess or groove 7 are of great importance inthe formation and maintenance of the oil seal and distribution of thelubricant, and the prevention of gas'leakage and loss of combustion andloss of the lubricant, by splashing, suction or injection into thecombustion chamber with consequent fouling by earbonization ofthe wallsof the combustion chamber and the cylinder head.

This groove is adjacent an axial end surface of the ring usually thebottom surface 51 as seated in operative position in a vertical engine.In the lower rings it is near the bottom surface, and in the upper ringsit may be turned toward the top surface to prevent leaka e of condensedfuel into the crank case. f less than a full set of these is used, thegrooved edges should be turned toward the crank. Where there are threeof the rings to a piston the top ring has the grooved edge turned un tocatch condensed fuel and prevent its passing the piston after the mannerdescribed in connection with the oil seal.

The oil sealing groove of the invention has ore surface or wall 71 atright angles to the outerperipheral or cylinder contacting face of thering, and to the axis of both, and incidentally to the cylinder walls,and to the direction of stroke of the engine, and the other wall 72inclined at an angle approximately half of a right angle to thecontacting face of the ring or otherwise expressed at an acute angle tothe saine. This atter wall or inclined surface intersects the axial endsurface 51 of the ring at the circumference, forming a peripheral edge52 in the plane of the cylinder contacting surface of the ring, whichthough engaging the cylinder wall, at the same time admits a smallquantity of oil to the sealing groove 7 on the down stroke and releasesa small quantity of oil on the up stroke, .forming a thin film on thesurface of the cylinder wall sufiicient for lubrication. On the otherhand, the surface 7l which is at 90 degrees to the direction of stroke,and to the axis of the ring, with the contacting surface above it,resists the passage of oil from this groove to the combustion space, andretains in the groove a quantity of cylinder oil, which fills allcrevices and irregularities in the cylinder wall, and acts as a seal,preventing' the, escape of gas.

The inner surface of the grooves 4 1s provided with a smaller annulargroove 8 int-o each of which latter a supplemental ring 9 is fitted;said rings 9 have their outer surface bearing against the inner surfaceof the piston rings. Leading from each of the grooves 4 and S are anumber of apertures 10 and 11, respectively, passing through the side ofthe piston to allow the oil to drop back into the crank case. lVlien thesupplemental ring is used and the piston 2 moves down, the rings 5 areagainst the top of their grooves which forces the oil under and back ofthe piston rings until it strikes the supplemental rings 9 which latterwill prevent the oil Working over the piston rings when the piston isforced up again, as in the case with the piston rings in present use.Vhen the oil strikes the supplemental rings 9 it will pass through theapertures l0 to the crank case, and any oil which might work back of thesupplemental rings 9 will drain through the apertures 11 and also dropback into the crank case.

In Fig. 3 I have shown a modificationof the piston ring 12, the samebeing made in two sections. The supplemental rings 9 fit closely in thegrooves 8 and at all times impinge against the piston rings, and are notaffected by centrifugal force or vacuum, and the oil that works underthe piston rings 12 will strike the supplemental rings 9 and pass offthrough the apertures l0 to the crank case, and any oil that may workback of said supplemental rings 9 will drain through the apertures 11and also drop back into the crank case.

While I have shown and described a piston ring with a groove in itsouter surface, and also a piston ring formed of two sections, any otherdesired forrn of piston ring may be employed with the supplemental ring,and the ring having the groove with the right-angular and inclined wallswith the oil distributing edge may be used in any desired combination orseparately.

By means of the new form of sealing groove 7 described above which maybe applied to any type of ring, the applicant has achieved an increasedeconomy of cylinder oil, and decreased the carbon deposit, and improvedthe sealing or packing effect of the ring.

The position of the sealing groove immediately adjacent the bottom oraxial end surface 51 of the ring with the inclined surface of the groove7 forming a cylinder wiping, oil distributing and regulating edge 52, bywhich oil is admitted in small quantities to the sealing groove anddistributed over the cylinder walls in combination with the rightangularsurface 71 and the flat peripheral cylinder contacting surface T3. bywhich the further passage of oil is limited to the minimum, and the oilaccumulated in the groi'lve forming a pulsating oil seal which wipes thecylinder walls with the piston strokes filling and closing all crevicesin the walls, preventing the loss of pressure and escape of gas is ofgreat importance.

Having thus described my invention, what I claim is:

l. The combinationof a piston ring having an annular groove in its outersurface provided with apertures leading to the inside of the piston anda .smaller annular groove at the back of the first named annular grooveand also provided with apertures leading from said smaller groove to theinside of the piston, a piston ring fitted in the said first-namedannular groove, and a supplemental ring fitted in said smaller annulargroove and impinging against the piston ring.

2. The combination of a piston having annular grooves in its outersurface each provided with apertures leading to the inside of the pistonand a smaller annular groove back of each of said first namedannula'rgrooves and also provided with apertures leading to the insideof the piston, a piston ring in each of said first named annular groovesand each having a recess in its outer face one surface of which is cutat right angles to the face of the rings and the other surface isinclined, and a supplemental ring fitted in each of said smaller annulargrooves and impinging against the piston rings.

3. A spring piston ring having its ends formed in a step joint, withsliding contacting surfaces and an annular groove in the peripheralsurface, said groove being spaced from the plane of contact of saidsliding surfaces, the ring having a peripheral flat surface adapted tobear on the cylinder Wall, and including the intersect-ion of said planeof contact of said sliding surfaces with the periphery of the ring, thegroove having a wall at right angles to the axis of the ring and a wallsharply inclined to said axis, the inclined Wall intersecting an axialend surface of the ring forming a peripheral annular edge of thediameter and circumference equal to those of the peripheral fiatsurface.

4. A spring piston ring having its ends formedin a step joint, withsliding contacting surfaces and an annular groove in its peripheralsurface adjacent one axial end surface, substantially all of theremainder of the peripheral surface being flat or straight in thedirection of the axis, said Hat surface, including the intersection ofsaid sliding surfaces with the periphery of the ring, so that the groovedoesl not intersect the sliding surfaces, one Wall of the groove beingsubstantially at right' angles to the axis of the ring, and another wallof the groove being sharplyr inclined to the axis and intersecting theaxial end surface of the ring, forming a peripheral edge of thecircumference and diameter equal to that of the peripheral flat surfaceof the ring.

5. A. spring piston ring having its ends formed in a set joint, withsliding contacting surfaces and an annular groove in its peripheralsurface adjacent one axial end surface, substantially all of theremainder of the peripheral surface being fiat or straight in thedirection of the axis, one Wall of the groove being substantially atright angles to the axis of the ring, and another Wall of the .groovebeing sharply inclined to the axis, forming a peripheral edge of acircumference and diameter equal to that of the peripheral Hat surfaceof the ring.

6. A one-piece spring piston ring for internal combustion engines,having a step joint at the meeting ends, with sliding, con tactingsurfaces; a peripheral plane surface to contact the cylinder walls, thesame including the intersection of the sliding, contacting surfaces withthe periphery; the ring also having a peripheral groove adjacent oneaxial end surface, the same being clear of the sliding surfaces so thatit does not intersect them; the groove having an inclined wallintersecting the adjacent end surface, forming a peripheral edge of adiameter and circumference equal to the outside diameter of the ring,which is adapted to contact the cylinder Walls and admit oil to thegroove, confining it therein, forming an oil seal and distributing oilin small quantities over the cylinder surface for lubrication.

Signed by me at Baltimore, Maryland,

this 13th day of November, 1919.

JOHN E. NORWOOD.

Witnesses:

PORTER H. FLAUTT, EMMA AHLSLEGLE.

